1. Field of the Invention
The present invention relates to a video camera, and more particularly to a monitor video camera that can operate in low visibility environments and during the night.
2. Description of Related Art
Monitoring video cameras are used generally in places such as banks or laboratories that have valuable properties such as cash, experiment instruments or computer hardware and documents, to record the actions of people in these places and prevent the unauthorized accesses to these valuable properties.
With reference to FIG. 3, a conventional monitor video camera is mounted on a ceiling and comprises a mounting bracket (50), two side tabs (51), a camera bracket (52), two printed circuit boards (PCBs) (54), a lens (53) and a transparent shell (55).
The mounting bracket (50) is mounted on the ceiling and has a bottom surface and a bottom outer edge.
The side tabs (51) are mounted on the bottom surface of the mounting bracket (50), are separate from each other and each side tab (51) has a distal end and a curved slot (510). The curved slot (510) is defined through the side tab (51) and close to the distal end.
The camera bracket (52) is mounted slidably and rotatably between the side tabs (51) and has two opposite sides and two sliding pins (520). The sliding pins (520) are mounted securely on the sides of the camera bracket (52) and extend slidably and rotatably through the curved slots in the side tabs (51).
The PCBs (54) are mounted through the camera bracket (52).
The lens (53) is mounted on the camera bracket (52) and is connected electrically to the PCBs (54).
The transparent shell (55) is mounted on the bottom outer edge of the mounting bracket (50) and covers the elements (51, 52, 53, 54).
However, the conventional monitoring video camera must be used in light and bright places or in daylight.
With reference to FIG. 4, an improved monitoring video camera is used in both dark and light places and comprises a mounting bracket (60), two side tabs (61), a stationary bar (62), a camera bracket (63), two camera control PCBs (64), a lens bracket (65), a lens (66), a light control PCB (67), a lens shade sleeve (68) and a transparent shell (69).
The mounting bracket (60) is mounted on a ceiling and has a bottom surface and a bottom outer edge.
The side tabs (61) are mounted on the bottom surface of the mounting bracket (60) and are separate from each other.
The stationary bar (62) is mounted on the bottom surface of the mounting bracket (60) and has a distal end and a protrusion formed on the distal end.
The camera bracket (63) is mounted rotatably between the side tabs (61) and has a sector top edge, multiple teeth (630) and a bottom surface. The teeth (630) are formed along the sector top edge of the camera bracket (60) and adjacent two of the teeth (630) engage with the protrusion on the stationary bar (62).
The camera control PCBs (64) are mounted on the bottom surface of the camera bracket (63), are located respectively on an upper position and a lower position and each camera control PCB (64) has a bottom surface.
The lens bracket (65) is mounted on the bottom surface of the lower camera control PCB (64) and has a bottom.
The lens (66) is mounted on the bottom of the lens bracket (65).
The light control PCB (67) is mounted around the lens bracket (65) and has a bottom surface and multiple light emitting diodes (LEDs) (671). The LEDs (671) are mounted on the bottom surface of the light control PCB (67) and are arranged circularly around the lens (66).
The lens shade sleeve (68) is made of foam rubber, is mounted between the LEDs (671) and the lens (66) and has a bottom end opposite to the bottom of the light control PCB (67).
The transparent shell (69) is mounted on the bottom outer edge of the mounting bracket (69) and has an inner surface abutting the bottom end of the lens shade sleeve (68).
When the improved monitoring video camera operates, the LEDs (67) illuminate surrounding environment so the monitoring video camera can take clear dynamic or static images. The lens shade sleeve (68) prevents light of excessive intensity from the LEDs (67) passing into the lens (67) as that excessive light would cause over-exposure of the negative.
However, the improved monitoring video camera has several disadvantages as follows:
1. The stationary bar (62) and the teeth (630) make the monitoring video camera expensive.
2. The sector top edge of the camera bracket (63) and the PCBs (64, 67) cause the volume of the improved monitoring video camera to be larger than that of the conventional monitoring video camera.
3. The lens shade sleeve (68) hardens and deforms after a period of time due to the high temperature of the LEDs (671) and loses its resilience so the bottom end of the lens shade sleeve (68) cannot abut the inner surface of the transparent shell (69) and causes excessive gaps between the lens shade sleeve (68) and the transparent shell (69) whereby over-exposure may be caused by stray light from the LEDs (671). To overcome the shortcomings, the present invention provides a monitoring video camera to mitigate or obviate the aforementioned problems.